Overflow tank for radiators



Sept. 19, 1933. H. w. LLOYD ET AL OVERFLOW TANK FOR RADIATORS MWI JH VHHHH ld I I Patented ESepl. 1%, F333 UNITED STATES PATENT OFFICEOVERFLOW TANK FOR RADIATOBS tion of New York Application June 9, 1930.

Serial No. 460,071

15 Claims- (Cl. 123-174) This invention relates to cooling systems forinternal combustion engines.

To carry away the heat of combustion, most internal combustion enginesare provided with jackets surrounding the cylinders and combustionchambers for the flow therethrough of water or the cooling medium whichabsorbs the heat. In the case of motor vehicles and other conveyances, aradiator may be used and the same cooling liquid is then passed back andforth between the radiator and engine jacket, an engine driven pumpgenerally being inserted in the system to continuously circulate thecoolant in such conventional constructions. An overflow pipe is alsoprovided to vent the system and prevent internal pressures by reason ofexpansion and contraction of the cooling liquid with temperaturechanges, and since the overflow liquid leaves the system, it becomesnecessary to replenish the supply from time to time. While the necessityfor replenishment is not ordinarily considered objectionable to the useof this type of cooling system on private pleasure automobiles whenwater is used as the coolant,'it does become an item for objection whenthe more expensive anti-freeze solutions are used, and more so when theengine is in long and hard service, as in the case of trucks and publicconveyances.

To provide a system which will effectually eliminate loss of coolingfluid without material changes in the construction and operation ofconventional systems by collecting and storing any overflow forsubsequent return to the main system as it is needed to maintain theamount of liquid in the main system substantially constant and thuseliminate the necessity for frequent replenishment, is one of theprimary objects of the present invention.

It is another object of the invention to provide an improved overflowsystem for temporary storage of excess liquid, which may be easily andquickly installed either as original equipment on new cars or asaccessory equipment for existing cooling systems.

A further object is to provide an improved storage tank and anautomatically controlled closure for the outlet therefrom leading backto the main circulatory system, so as to preclude the entrance of airand the formation of air pockets and steam in the engine jackets, whichwould reduce cooling efiiciency.

The invention aims also to impose restraint on the action of the closuremember, as for example, by means of a dash pot or other friction device,so as to overcome any tendency of the closure member to vibrate orflutter, particularly when in closed position, because of either enginevibration, rough movement of the vehicle, liquid surge, or the like.

Various other objects and advantages of the invention will be apparentfrom the following detail specification, taken in connection with theaccompanying drawing, which illustrates a preferred but not necessarilythe only embodiment. In the drawing, Figure l is a side elevation of anengine and its cooling system, as employed on an automobile, with whichthere is associated the overflow system, forming the.pr esent subjectmatter. Figure 2 is a detail view of the overflow tank with partsthereof in section. Figure 3 is a transverse section taken on line 3-3of Figure 2.

Referring to the drawing, the reference numeral 1 indicates an internalcombustion engine of the multiple cylinder type as used on automobilesand which is located beneath a hood or bonnet 2 between the dash board 3of the body, and a radiator 4. The radiator 4 is shown as of theconventional type having an intermediate cooling core, an upper headeror intake tank, and a lower header or outlet tank. Behind the radiatoris a fan 5 for drawing a current of air through the cooling core, theshaft of which carries a pulley to be driven by a belt 6 from the enginecrank shaft. This fan shaft may also drive a pump 8 associated withcooling jacket of the engine 1 for forcing water or other cooling mediumtaken from the bottom of the radiator 4, through a tubular connection 9,between'the outlet header and intake side of the pump, through theengine jacket and then through the outlet therefrom, which is connected,as by means of a flexible hose or tube 10, with the inlet header of theradiator. The construction thus far described constitutes a conventionalcooling system used on practically all motor vehicles and in which theengine drives a pump for circulating the cooling liquid back and forthbetween the engine and cooling radiator and also a fan to induce adraught or air current through the radiator, where the heat ofcombustion is dissipated to the air stream.

To take care of liquid expansion, an overflow pipe 13 customarily islocated in the top tank and extends out through the wall thereof, andthen down the side of the radiator to a point where the overflow will bedischarged to the ground. In the present case it is proposed to connectthe overflow 'pipe as by means of a short coupling 14, to one end of alength of tubing 15, which for mounted on the dash board 3 as by meansof a convenience and appearance purposes, may extend down the side ofthe radiator and then rearwardly beside the usual chassis frame memberand then upwardly, at a point adjacent the dash 3, where its oppositeend may be connected to the -intake of an overflow tank or storagereceptacle, indicated at 16.

For convenience and economy of manufacture, the overflow tank mayconsist of a length of seamless tubing, or it may be rolled from flatstock and united along its edges to form a tubular member, the ends ofwhich may be closed by the cup shaped walls 1'7 and 18,respectively,'the annular flanges of the, end walls being suitablyJoined and sealed, as for example, by means of soldering, welding,brazing, or the like. To facilitate installation, the overflow tank ispreferably bracket, that shown in the drawing consisting of a U-shapedmember 20 having out turned arcuate end flanges 21 for contact with thecylindrical wall of the tank 16, and being provided in each leg with anelongated'slot, through which extends a contractible ring or hoop 22,that terminates in lateral projections or ears, through which passes astud 23, for drawing the ends together and contracting the ring tosecurely hold the tank in place.

The upper wall 17 carries an apertured nut 25 to receive an elbowfitting 26, having threaded therein a short tubular extension 27 forattachment as by means of the coupling 28 with the adjacent end of theoverflow pipe 15. To vent the overflow tank, the top wall 1'? may alsobe provided with a small aperture, or it may be found more desirable toprovide a reversely bent or a U-shaped piece of tubing, as at 30, whichextends through the walland overthe side of the tank. In some cases itmay be considered advisable to clip oil the customary overflow pipe 13,adjacent its upper end, for attachment with the pipe 15, and then usethe clipped off part that normally extends down the side of the radiatoras an extension of the U-shaped tube 30. This expedient is illustratedin Figure 1 where the piece of tubing, indicated by the referencenumeral 31 and attached by the coupling part 32, represents that part ofthe normal overflow pipe 13, which was clipped off. In this way, ifthere should be any overflow from the tank 16, the discharge would be ata point below anything that could be harmed. It may. be statedincidentally, that if the storage tank is properly chosen for theparticular system with which it is to be used, its capacity will be suchthat there will seldom if ever be any overflow thru the pipe or tube 30.

extends thru the aperture into threaded engagement with one end of afitting 36, there being a gasket or washer 37 interposed between the endof the fitting and adjacent portion of the wall 18. to seal theconnection against leakage. At its opposite end the fitting 36 is closedby a plug 38 and intermediate its ends there is provided a screwthreaded opening to receive one end of the'pipe section 39, whoseopposite end carries an elbow fitting 40. In the upstanding leg of theelbow fitting 40, is located a ball or check valve 41, held in place bythe transverse pin 42, to prevent back fiow through the return line, aswill be later referred to. A short length of tubing 43, provides for theattachment, by meanslof a Leaner-2" consist of a short length strap ofU-section, bent to an inverted U-shape with inturned attachment feet forthe connecting rivets. At its upper top center, the cage 51 carries abearing disc orv washer 52, preferably formed of fibre and apertured forthe projection therethrough, of a stem or shaft 53, to guide the same.As shown in the drawing, this shaft 53 has fixedly secured thereon aball or float 54, which may consist of two semi-spherical metal cupssecured together, and just below the ball the shaft carries a sleeve 55,having its lower end tapered or conical shaped for seating engagementwith the upper side of the nut 35, to constitute a valve or closure forthe outlet, leading from the tank. This valve or closure is normallyheld on its seat by gravity when the tank is empty and is automaticallyopened when the level of water stored in the tank reaches 'a point tofloat the ball 54 and thereby move the valve of! its seat. The shaft 53is shown as projecting or extending into the fitting 36 and carrying atits lower end and below the connection with the pipe 39, a piston ormovable wall 56, slidable in the bore of the fitting. This piston andthe cooperating fitting wall provides a dash pot to check the movementof the fioat'54 to prevent its bobbing up and down due to sum!- Theoverflow unit is such that it may be easily.

and quickly installed with a minimum of labor and at low cost. Assumingthat installation has been made and that the engine is ready foroperation, the main cooling system is then filled lit ran

with water or whatever coolant it is desired to use, until the liquidlevel reaches the top of the overflow pipe 13. When the engine isstarted the pump immediatelycirculates the liquid through the mainsystem and the heat of combustion absorbed in the engine jacket isdissipated in the,

radiator. At this time the sleeve or valve 55 is held on-its seat bygravity, thereby precluding the intake of airthrough the vent 30 andtubing 45 under influence ofpump suction. As the liq- .uid warms up italso expands, and such expan-.

sion forces part of the liquid into the overflow pipe 13 and tubing 15into the top of the tank 16. Excess water is discharged from the mainsystem so long as expansion occurs, but instead of being discharged tothe ground and forever lost, it is'saved by being temporarily stored inthe tank 16. So soon as the liquid level in the tank raises to asufiicient height to float the ball 54, the valve 55 is lifted away fromits seat,

such movement. being permitted to take place.

slowly, by reason of the frictional resistance of the dash pot. With thevalve 55 open, the liquid is free to return thru the line 45 under pumpsuction, whenever contraction of liquid in the main system occurs andthelevel or volume diminishes. It will be understood that the returnordinarily will not occur until after the operation of the engine hasstopped and suflicient time elapsed to permit the liquid in the mainsystem to become cool. Whenever the engine is again operated, the actionof the pump will serve to draw in the water from the auxiliary circuitto the main circuit to replenish the supply until the liquid level inthe auxiliary tank falls and permits the float 54 to descend and closethe return line through the valve 55, to preclude entrance of air to thejacket from the vented tank and through the return line 45. Whenexpansion of the liquid in the main circuit once more occurs, the actionof the overflow repeats itself, and thus at no time does the supply ofliquid completely leave the cooling system and, therefore, losses do notoccur, and the necessity for frequent replenishment is eliminated.

The invention will be particularly useful in those cases where asolution such as a mixture of alcohol and water is employed as thecoolant, inasmuch as any alcohol vapors which would tend to leave themain cooling system must first pass through the long overflow pipe 15before reaching the air vent, and inasmuch as a certain amount of liquidwill also be present in the line 15, the vapors will be condensed beforereaching the air vent at the overflow tank. Furthermore, any liquidpassing through the pipe 15 will give oflE some of its heat beforereaching the tank, and as the result there will be but little vapor lossat the tank.

At such times, as when the engine is not in operation, there wilLbe atendency for the water to flow from the main system into the overflowtank through the return line 45 to reach its own level, but this iseffectually prevented by the provision of the check valve 41in thereturn line, whichiallows flow in one direction only.

We claim:

1. In a cooling system for internal combustion engines, a maincirculatory system; a receptacle vented to atmosphere and adapted fortemporarily storing excess cooling medium, a return line between saidreceptacle and the main circulatory system, a valve in the return lineactuating means for the valve controlled by the body of cooling mediumin said tank and adapted to close the valve when the receptacle isemptied and thereby prevent the entrance of air into the maincirculatory system.

2. In a cooling system for internal combustion engines, a maincirculatory system; a receptacle vented to atmosphere and adapted fortemporarily storing excess cooling medium, a return line between saidreceptacle and the main circulatory level system and controlled means inthe receptacle to close the return line against the entrance of air tothe main system.

3. In a cooling system for internal combustion engines, a maincirculatory system; a receptacle vented to atmosphere and adapted fortemporarily storing excess cooling medium, a return line between saidreceptacle and the main circulatory system, means to prevent the passageof air through the return line when the receptacle is empty and othermeans associated with said return line to check the back flow of coolingmedium therethru.

4. In a cooling system for internal combustion engines, a maincirculatory system; a receptacle vented to atmosphere and adapted fortemporarily storing excess cooling medium, a return line between saidreceptacle and the main circulatory system and a float controlledclosure for the return line to close the line against the flowof airtherethru when the cooling medium in said receptacle falls below apredetermined level.

5. In a cooling system for internal combustion engines, a maincirculatory system; a receptacle vented to atmosphere and adapted fortemporarily storing excess cooling medium, a return line betweensaidreceptacle and the main circulatory system and a float controlledclosure for the return line to close the line against the flow of airtherethru when the cooling medium in said receptacle falls below apredetermined level and means to retard the movement of said closure.

6. In an engine cooling system, an overflow tank for temporarily storingexcess liquid for subsequent return to the system, a valve for openingand closing the liquid outlet therefrom and a float operativelyconnected with the valve to control the action of the valve inaccordance with liquid level.

7. In an engine cooling system, an auxiliary tank for temporarilystoring expansion liquid for subsequent return to the system, a valvefor opening and closing the liquid outlet therefrom and float meansassociated with the tank to automatically control the valve.

8. In an engine cooling system, an auxiliary tank for temporarilystoring expansion liquid for subsequent return to the system, a valvefor opening and closing the liquid outlet therefrom, liquid leveloperated means associated with the valve to open and close the same, andother means to steady the action of said liquid level operated means.

9. In an engine cooling system, an auxiliary tank to temporarilystoreexpansion liquid for subsequent return to the system, a return lineleading from the tank, and a float controlled device associated with thereturn line to open and close the same.

10. In an engine cooling system, an auxiliary tank to temporarily storeexpansion liquid for subsequent return to the system, and a float controlled device governing the return of liquid to the system togetherwith means to damp the response of said device to changes in liquidlevel.

11. For use with an engine cooling system wherein an engine driven pumptakes the cooling liquid from the radiator outlet and forces it thru theengine jacket to the radiator inlet, .125 means to receive excess liquidupon expansion of the liquid supply in the system for subsequent returnto replenish the liquid supply, including a storage tank vented toatmosphere, an overflow connection between the system and said tank, anda return connection from the tank to the suction side of the pump, thruwhich liquid in the tank may be drawn back to the system under influenceof the pump together with a liquid level controlled device in the tankto close the outlet therefrom after the overflow has been returned so asto preclude the'intake of air to the system and the formation of airpockets in the engine jacket.

12. An engine cooling system, including a main circuit in which a pumpdraws cooling liquid from the outlet side of a. radiator and forces itthru the engine jacket to the intake side of the radiator and anaiixiliary circuit in which a tank for the temporary storage of liquidexpelled from the main circuit upon expansion, communicates with themain circuit by an overflow passageway and a return flow passageway,characterized by means to connect the return flow passageway on thesuction side of the pump, other means to 1 vent the top of the storagetank, and a liquid level operated closure device in said tank for thereturn flow passageway to preclude air reaching the engine jacket thrusaid passageway.

13. In an engine cooling system, an overflow tank to temporarily storeliquid expelled from the system upon expansion, for subsequent return tothe system, said tank having an outlet, a

valve controlling the tank outlet, 2. float in theeratively connectedwith the valve to control the valve in accordance with liquid level, anda connection between the float and said piston to retard the action ofthe float.

15. In a cooling system for internal combustion engines, a maincirculatory system for cool-- ing medium, a pump in said system forcirculating the cooling medium, an over-flow tank to receive andtemporarily store cooling medium expelled from the'main system, asuction line between said tank and the suction side of said pump for thereturn flow of cooling medium from the over-flow tank back to the mainsystem, and means operated independently of suction to automaticallyclose the return line against the passage of air when the tank is empty.

HERBERT W. LLOYD. J. R. HOLMES.

